After defeating Bosol (The final boss) go to the 1st floor and DO NOT go to Nell's room first. On the 1st floor go to the EPS room, cut the barbed wire and there will be 2 coins and a room 301 key.

Barbed wire fence to cut

Go to the 3rd floor and open room 301.

3rd floor room 301

DO NOT SHOOT THE NURSES!!
- After walking out of the room and closing the door, walk away a nurse will say "Thank you" and you will get the achievement.
- If you go back in the room after hearing the thank you there will be 3 coins on the table

Cheeks